New Delhi: The central government's air monitoring body showed "very poor" quality of air in the national capital on Thursday, but the city government claimed that pollution level on Diwali this year was lower compared to last year.
The System of Air Quality and Weather Forecasting and Research (SAFAR) of the union ministry of earth sciences shows the PM 2.5 level -- Particulate Matter with a diameter smaller than 2 1/2 microns which can cause harm to breathing -- at 229.5 units. It said the air quality was "very poor".
Representational picture. Photograph by: Bipin Kokate
These PM 2.5 levels had touched alarming heights over 400 units about 11 p.m. on Diwali night on Wednesday -- falling under "severe" air condition, according to SAFAR. The Delhi Pollution Control Committee (DPCC), however, compared this year's pollution level with the past year and said that pollution level this Diwali was lower.
The data from DPCC, a Delhi government agency, revealed that the maximum average values of SO2, NO2 and PM 2.5 were lower on this Diwali compared to their corresponding values on the same occasion in 2014. The Ambient Air Quality monitoring was conducted at six Locations -- R.K. Puram, Mandir Marg, Punjabi Bagh, Civil Lines, Anand Vihar and the Indira Gandhi International airport.
"This year on Diwali Day, the average concentration of NO2 varied from 37.0 ug/m3 to 79.0 ug/m3 whereas last year, the average concentration of NO2 varied from 39 ug/m3 to 194 ug/m3," a Delhi government statement said.
"Similarly this year on Diwali Day, the average concentration of SO2 varied from 26 ug/m3 to 64 ug/m3, whereas last year the average concentration of SO2 varied from 8 ug/m3 to 87 ug/m3. The minimum average value was observed at IGI airport and maximum average value was observed at Anand Vihar," it added.
As per the DPCC, the average concentration of PM 2.5 (for 24 hours) ranged from 184 ug/m3 to 369 ug/m3 this Diwali. Last year on Diwali day, the average concentration of PM 2.5 ranged from 145 ug/m3 to 500 ug/m3. According to Vikrant Tongad, an environmental expert, it would take at least a week or more for the pollution caused by Diwali in the air to dilute to normal levels as they were pre-Diwali.
"Due to awareness among people this time, less fire crackers were used in a compared to previous years. Even if used, the crackers were environment friendly. It would still take about a week for the air to take its previous shape," Tongad told IANS. Tongad said the recent crop burning in the northern belt of the country -- Punjab, Delhi, Haryana and Chandigarh -- made a great contribution to this rise in PM 2.5 levels.
The Delhi government had taken steps to contain the air pollution levels in the national capital during Diwali festival through a multi-pronged strategy by launching "Say No To Fire Crackers" campaign with the support of schools/colleges and residence welfare associations.
An analysis from the DPCC shows the PM 2.5 levels have been seen increasing in the recent past seven times to what they were on October 1. "This leaves no room for additional pollution in the city especially from crackers that not only pushes up the pollution spike but also laces it with deadly cancer causing substances," said Centre for Science and Environment (CSE) executive director Anumita Roychowdhury in a recent study.
SAFAR said before Diwali that the PM 2.5 levels could reach as high as 429 units, registering a "critical" quality of air. It also predicted that the air levels would remain "poor" for the next three days.